This invention generally relates to the field of docklevelers that provide a bridge between a loading dock and a vehicle (e.g., a truck or a trailer) positioned at the loading dock.
Docklevelers typically include a deck for bridging the space between a loading dock and a vehicle. The deck commonly is pivotally attached to the loading dock and is movable between a declined lowered position, a horizontal stored position, and an inclined raised position. A lip is usually mounted to the outer end of the deck and is disposed in an pendent inoperative position when the deck is in the stored position. In this stored position, the deck is supported by the pendent lip, which is engaged with a lip support. In operation, the deck is lifted to the raised position, then subsequently lowered while moving the lip from the pendent position to an extended operative position. The deck continues to lower until the lip engages the vehicle, and the lip provides support for the outer end of the deck.
In certain loading situations, the lip cannot be moved to the operative position due the positioning of a load on a vehicle. For example, the load may be positioned too close to the end of the vehicle, thereby not providing sufficient space for full extension of the lip. This situation is commonly called an xe2x80x9cend load.xe2x80x9d In order to remove an end load, the dockleveler must be positioned in either the horizontal stored position or the lowered position with the lip in the pendent inoperative position. A fork lift can then be positioned on the deck and used to lift the end load from the vehicle. After the end load is removed, the dockleveler can be raised an then lowered to rest the lip on the vehicle.
Some loading docks include a barrier that inhibits material handling equipment (e.g., fork lifts) from accidentally falling off the end of the deck when the deck is in the stored position. One type of barrier is a lip barrier that is incorporated into the lip of the dockleveler, as disclosed in German Patent Nos. DE2634652 and DE2852888. When the lip is in the extended operative position, the lip barrier is designed to be in a non-blocking position that is below or flush with an upper surface of the deck. When the lip moves to the pendent inoperative position, the lip barrier raises to a blocking position that is above the upper surface of the deck, thereby inhibiting material handling equipment from rolling off the outer end of the deck.
Lip barriers are simple, reliable barriers that are raised to the blocking position when the lip is pendent. One problem with this design is that it can prevent unloading an end load. That is, with the lip pendent, the raised lip barrier can impede the ability of a fork lift to access the end load. Another problem with the basic lip barrier design is that it is very rigid and can be easily damaged by even a slight impact of a fork lift. Any bending of or damage to the barrier will require repair of the dockleveler. The rigid barrier can also disrupt a load carried by the fork lift.
The dockleveler described herein has several distinct features that provide important advantages over the basic lip barrier design. One such feature is the provision of a lip that can be both moved between a pendent inoperative position and an operative position and moved from a retracted to an extended position. This feature allows the lip to be partially extended during an end load so that the lip engages a portion of the vehicle bed and does not contact the load.
Another distinct feature is the provision of a barrier that is resiliently mounted to provide a cushioning effect when impacted by material handling equipment. This feature reduces the likelihood of damage to the barrier and/or dockleveler, and further reduces the chance of disrupting a load carried by the material handling equipment.